Planetary wheel end assemblies include a planetary gear assembly that receives driving input from an axle shaft. A typical planetary gear assembly includes a sun gear that is fixed for rotation with the axle shaft, a plurality of planet gears, a ring gear, and a planetary spider that supports the planet gears. In one known configuration, the ring gear is fixed to a non-rotating component, such as a housing for example, and the planetary spider provides driving output for a wheel component.
In certain applications the planetary wheel end assembly also includes a wet disc brake. The wet disc brake includes stationary discs fixed to the housing and rotating discs that are fixed for rotation with the axle shaft. Due to the high speed at which the rotating discs rotate, any out of center condition can generate high centrifugal forces that can cause the sun gear to become mis-aligned. This can result in noise, vibration, and reduced wear life for the gears. Solutions have been proposed to address this out of center condition but these solutions have been proven to be expensive and ineffective.